Summary of treatment of acute TMA in pregnancy. Highlighted are the conditions that may present as TMA in pregnancy. Pregnancy-related TMAs generally require delivery. TTP and CM-HUS may present features of pregnancy-related TMAs but require a different pathway in part dictated by the ADAMTS-13 activity level. TTP is diagnosed when ADAMTS-13 activity is less than 10 IU/dL but may be up to 20 IU/dL before TTP can be excluded. Repeat ADAMTS-13 activity samples and ADAMTS-13 antibody should be checked.